STARTUP.A51
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上传日期:2019-09-13
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- $NOMOD51
- ;------------------------------------------------------------------------------
- ; This file is part of the C51 Compiler package
- ; Copyright (c) 1988-2002 Keil Elektronik GmbH and Keil Software, Inc.
- ;------------------------------------------------------------------------------
- ; STARTUP.A51: This code is executed after processor reset.
- ;
- ; To translate this file use A51 with the following invocation:
- ;
- ; A51 STARTUP.A51
- ;
- ; To link the modified STARTUP.OBJ file to your application use the following
- ; BL51 invocation:
- ;
- ; BL51 <your object file list>, STARTUP.OBJ <controls>
- ;
- ;------------------------------------------------------------------------------
- ;
- ; User-defined Power-On Initialization of Memory
- ;
- ; With the following EQU statements the initialization of memory
- ; at processor reset can be defined:
- ;
- ; ; the absolute start-address of IDATA memory is always 0
- IDATALEN EQU 80H ; the length of IDATA memory in bytes.
- ;
- XDATASTART EQU 0H ; the absolute start-address of XDATA memory
- XDATALEN EQU 0H ; the length of XDATA memory in bytes.
- ;
- PDATASTART EQU 0H ; the absolute start-address of PDATA memory
- PDATALEN EQU 0H ; the length of PDATA memory in bytes.
- ;
- ; Notes: The IDATA space overlaps physically the DATA and BIT areas of the
- ; 8051 CPU. At minimum the memory space occupied from the C51
- ; run-time routines must be set to zero.
- ;------------------------------------------------------------------------------
- ;
- ; Reentrant Stack Initilization
- ;
- ; The following EQU statements define the stack pointer for reentrant
- ; functions and initialized it:
- ;
- ; Stack Space for reentrant functions in the SMALL model.
- IBPSTACK EQU 0 ; set to 1 if small reentrant is used.
- IBPSTACKTOP EQU 0FFH+1 ; set top of stack to highest location+1.
- ;
- ; Stack Space for reentrant functions in the LARGE model.
- XBPSTACK EQU 0 ; set to 1 if large reentrant is used.
- XBPSTACKTOP EQU 0FFFFH+1; set top of stack to highest location+1.
- ;
- ; Stack Space for reentrant functions in the COMPACT model.
- PBPSTACK EQU 0 ; set to 1 if compact reentrant is used.
- PBPSTACKTOP EQU 0FFFFH+1; set top of stack to highest location+1.
- ;
- ;------------------------------------------------------------------------------
- ;
- ; Page Definition for Using the Compact Model with 64 KByte xdata RAM
- ;
- ; The following EQU statements define the xdata page used for pdata
- ; variables. The EQU PPAGE must conform with the PPAGE control used
- ; in the linker invocation.
- ;
- PPAGEENABLE EQU 0 ; set to 1 if pdata object are used.
- ;
- PPAGE EQU 0 ; define PPAGE number.
- ;
- PPAGE_SFR DATA 0A0H ; SFR that supplies uppermost address byte
- ; (most 8051 variants use P2 as uppermost address byte)
- ;
- ;------------------------------------------------------------------------------
- ; Standard SFR Symbols
- ACC DATA 0E0H
- B DATA 0F0H
- SP DATA 81H
- DPL DATA 82H
- DPH DATA 83H
- NAME ?C_STARTUP
- ?C_C51STARTUP SEGMENT CODE
- ?STACK SEGMENT IDATA
- RSEG ?STACK
- DS 1
- EXTRN CODE (?C_START)
- PUBLIC ?C_STARTUP
- CSEG AT 0
- ?C_STARTUP: LJMP STARTUP1
- RSEG ?C_C51STARTUP
- STARTUP1:
- IF IDATALEN <> 0
- MOV R0,#IDATALEN - 1
- CLR A
- IDATALOOP: MOV @R0,A
- DJNZ R0,IDATALOOP
- ENDIF
- IF XDATALEN <> 0
- MOV DPTR,#XDATASTART
- MOV R7,#LOW (XDATALEN)
- IF (LOW (XDATALEN)) <> 0
- MOV R6,#(HIGH (XDATALEN)) +1
- ELSE
- MOV R6,#HIGH (XDATALEN)
- ENDIF
- CLR A
- XDATALOOP: MOVX @DPTR,A
- INC DPTR
- DJNZ R7,XDATALOOP
- DJNZ R6,XDATALOOP
- ENDIF
- IF PPAGEENABLE <> 0
- MOV PPAGE_SFR,#PPAGE
- ENDIF
- IF PDATALEN <> 0
- MOV R0,#LOW (PDATASTART)
- MOV R7,#LOW (PDATALEN)
- CLR A
- PDATALOOP: MOVX @R0,A
- INC R0
- DJNZ R7,PDATALOOP
- ENDIF
- IF IBPSTACK <> 0
- EXTRN DATA (?C_IBP)
- MOV ?C_IBP,#LOW IBPSTACKTOP
- ENDIF
- IF XBPSTACK <> 0
- EXTRN DATA (?C_XBP)
- MOV ?C_XBP,#HIGH XBPSTACKTOP
- MOV ?C_XBP+1,#LOW XBPSTACKTOP
- ENDIF
- IF PBPSTACK <> 0
- EXTRN DATA (?C_PBP)
- MOV ?C_PBP,#LOW PBPSTACKTOP
- ENDIF
- MOV SP,#?STACK-1
- ; This code is required if you use L51_BANK.A51 with Banking Mode 4
- ; EXTRN CODE (?B_SWITCH0)
- ; CALL ?B_SWITCH0 ; init bank mechanism to code bank 0
- LJMP ?C_START
- END